(aside: everybody please read ‘Considered Harmful’ Essays Considered Harmful. Thank you)
But the real point is that you can’t just blindly follow results from a tool for what are ultimately stylistic issues like these. You have to use your knowledge as a programmer to interpret the output and agree / disagree with each point as appropriate. The purpose of JSLint is to flag areas that might be of concern, or perhaps be liable to bugs. It’s not saying “this is a bug, absolutely, for sure”.
One thing which might be useful (although I have no idea how easy it would be to implement) would be to be able to specify hints in the same manner that you could for C lint. There is already one example (declaring external definitions), but there could be more.